Revised Valve Train Parts to Reduce a Warm Engine Tapping or Sewing Machine type Sound from the Left Cylinder Head

INTRODUCTION

This bulletin announces the availability of revised valve train components developed to reduce a tapping sound which may be heard coming from the left-hand (B2) side of the engine when the engine is warm. This bulletin does not address any cold engine or start-up sounds. The changes consist of:

The illustrations below show additional information about the changes to the valve rockers, camshafts and valves to help readily distinguish them from the previous version parts.

SERVICE PROCEDURE / INFORMATION

If you receive a customer concern of a tapping sound from the B2 cylinder head, confirm it is isolated to the B2 valve train area before proceeding with any repairs. Once verified, order and replace all 4 intake and all 4 exhaust valves, all 8 rockers, both the intake and the exhaustcamshaft and all 8 rocker arm pivots (Replace the rocker arm pivots only if the VIN is prior to the listed VIN breakpoint shown in the Parts Information area of this bulletin) as a set using the part numbers shown in this bulletin (in addition to the necessary gaskets and seals). Refer to the service procedures outlined in the applicable Service Manual for installation.

NOTE: When resetting the valve clearances, the intake should be set to 0.13mm +0.02 / – 0.03 and the exhaust should be set to 0.22mm +/- 0.02. These are revised specifications and not reflected in the Service Manual.

IMPORTANT: Do not mix old and new parts together or mix parts between the left and right cylinder head as it will become impossible to obtain valve clearances that are within specification.

TIP: An egg carton makes a perfect organizer tray. Make sure to mark it as necessary (front, intake, exhaust) to eliminate any mixing of parts.

WARRANTY / CLAIM INFORMATION

For vehicles within the Basic New Car Limited and/or Powertrain Warranty, this repair may be claimed using the following information: